Sony’s new 4K A Series camera has no OLPF but has S-Log2 and 42MP
Posted on Jun 11, 2015 by Julian Mitchell
The new α7R II interchangeable lens camera features the world’s first back-illuminated full-frame Exmor R CMOS sensor, which delivers 42.4 MP approx. effective megapixels, high sensitivity (expandable up to ISO 102400 (stills only) and high speed AF response up to 40% faster than the original α7R thanks to 399 focal plane phase detection AF points.
Sony are piling on the commercial pressure for its competitors with the launch of another feature packed ‘a’ series camera with 4K video performance. Their new α7R II camera shoots in 4k quality (QFHD 3840×2160) in either Super 35mm crop mode or full-frame mode.
In Super 35mm mode, although capturing 1.8x as many pixels as 4K by using full pixel readout there is none of that ruthless pixel binning but oversampling to produce 4K movies with minimal moire and ‘jaggies’. Sony has chosen not to include an optical low pass filter on the camera probably hoping that the higher resolution sensor with more and smaller pixels will be enough to lessen moire and false colour.
In full-frame mode, the α7R II uses the full width of the 35mm sensor for 4K recording. Is this the world’s first digital camera to offer this in-camera full-frame format 4K recording capacity? Sony think it is. They use their XAVC S codec during video shooting, which records at 100 Mbps during 4K recording and 50 Mbps during full HD shooting.
To really attract the pro shooter there’s also Picture Profiling, S-Log2 Gamma and S-Gamut. Slomo is in the iPhone 6 class of 120fps in 720p but there is time code and a clean HDMI output for out board recording.
The new flagship α7R II model also has a 5-axis image stabilisation system which is similar to the system launched on the α7 II model. The system corrects camera shake along five axes during shooting, including angular shake (pitch and yaw) that tends to occur with a telephoto lens, shift shake (X and Y axes) which becomes noticeable as magnification increases, and rotational shake (roll) that often affects video recording. Sony claim the compensation is equivalent to shooting at a shutter speed approximately 4.5 stops faster.
The 42.4 MP sensor combines gapless on-chip lens design and AR (anti-reflective) coating on the surface of the sensor’s glass seal to improve light collection efficiency, resulting in high sensitivity with low-noise performance and wide dynamic range. This allows the camera to shoot at an ISO range of 100 to 25600 that is expandable to ISO 50 to 102400 but the highest ISO figure is only for still images, we’re not sure what the video capture highest ISO figure is yet.
Additionally, the sensor’s back-illuminated structure, with an expanded circuit scale and copper wiring design, enables faster transmission speed and ensures content can be captured in high resolution without sacrificing sensitivity. Data can also output from the sensor at an approximately 3.5x faster rate compared to the original α7R so less chance of rolling shutter artefacts .
The α7R II has a new reduced-vibration shutter that delivers 50% less vibration from shutter movements compared to its predecessor, and has a cycle durability of approximately 500,000 shots. The camera can also be set to Silent Shooting mode in order to shoot images quietly without any sensor vibration or movement.
The new image sensor features 399 focal-plane phase-detection AF points that work together with 25 contrast AF points to achieve focus response that is about 40% faster than the original model. The α7R II utilises an advanced motion-detection algorithm combined with this Fast Hybrid AF system to achieve up to 5fps continuous shooting with AF tracking.
The new α7R II camera is Wi-Fi® and NFC compatible and fully functional with Sony’s PlayMemories Mobile application available for Android and iOS platforms, as well as Sony’s range of PlayMemories Camera Apps, which add a range of creative capabilities to the camera. For example, there is help for time-lapse photography thanks to a new “Angle Shift add-on” app allows users to add pan, tilt and zoom to time-lapse images without any additional shooting equipment or PC software required. Learn more at www.sony.net/pmca.
Sony has also introduced a new LCD monitor model CLM-FHD5, an ideal companion to the α7R II for video shooting. A compact 5.0 type Full HD (1920x1080p) LCD monitor, the CLM-FHD5 features enlarging and peaking functionality for precise focusing, false colour and video level marker for adjusting exposure and S-Log display assist to assist S-Log shooting.
The α7R II will start shipping in Europe in Summer 2015 and will be priced at approximately €3,500.
